Compact instantaneous water heater



Filed Oct. 23, 1962 2 Sheets-Sheet 1 Fig. l

June 22, 1965 KINGO MIYAHARA COMPACT INSTAN'IANEOUS WATER HEATER 2Sheets-Sheet 2- Filed Oct. 23, 1962 Fig. 7

United States Patent 3,190,283 COMPACT INSTANTANEOUS WATER HEATER KingoMiyahara, 45 Miyarnaecho, Meguro-iru,

Tokyo, Japan Filed Oct. 23, 1962, Ser. No. 232,411 2 Claims. (Cl.126-459) define the top portion of a combustion chamber and having awall formed with through apertures serving as outlet openings allowingburnt gases to flow exteriorly of said combustion chamber, a stack ofheat-absorbing material filling a space defined between said cap memberand the adjacent wall of said casing, means for sprinkling water oversaid stack of heat absorbing material, and

means for collecting the water heated.

In the water heater according to the present invention, sprinkled watercomes into direct contact with the burnt gases or the heat absorbingmaterial heated thereby to be heated through the heat exchange efiectedtherebetween while trickling down through the stack of heatabsorbingmaterial and the water thus heated is collected in the water collector.

The water heater according to the present invention is a kind of flushtype water heater which is highly eificient, compact and economical tomanufacture. The waterheater may be advantageously employed in all caseswhere heated water is required either for domestic or industrial use.

The present invention will now be described in detail with reference tothe accompanying drawings, which illustrate a few embodiments of theinvention and in which:

FIG. 1 is a vertical cross-sectional view of one embodiment of theinvention;

FIG. 2 is a top plan view of the embodiment shown in FIG. 1;

. FIG.,3 is a side elevational view of a modified form I of cap member;

FIG. 4 is an enlarged fragmentary cross-sectional view of the cap membershownin FIG. 3;

FIG. 5 is a vertical cross-sectional view of another embodiment of thepresent invention;

FIG. 6 is a top plan view of the embodiment shown in FIG. 5; and

FIGS. 7 and 8 are a side elevational and a top plan view, respectively,of the cap member employed in the embodiments of FIGS. 5 and 6.

Referring to the drawings and particularly to FIGS. 1 and 2, the waterheater illustrated is comprised of a base 10, a casing mounted on thebase. A cover is disposed on top of the casing, and a cap-like member 4bis mounted in the casing. A burner assembly 50 is arranged in the baseon the bottom thereof. A stack of solid heat-absorbing refractorymaterial 60 fills a space defined between the cap-like member 44 and theadjacent wall of the casing 20 to surround the cap-like member 40. Waterfeeding means 713 is provided for sprinkling water over the stack ofheat-absorbing material. The heat-absorbing material preferably takesthe form of pebbles of fora-ruinous rock such as of silica, shale orpumice or ceramic material or balls formed of sheet metal.

The base 10 is preferbly a one-piece structure of cast iron having acylindrical side wall 11, a bottom wall 12 and an annular flange 13extending horizontally inwardly ice from the side wall 11 at a levelabout half of the height thereof.

The casing 21) is made of sheet metal and has a cylindrical outer shellor wall 21 connected at the bottom end with an annular bottom wall 22along the outer periphery thereof. A relatively short cylindricalupstanding wall 23 extends upwardly from the inner peripheral edge ofthe annular bottom 22. The walls 21, 22 and 23 together form a reservoir24 where heated water collects. Provided inside of the outer casing wall21 is an inner shell or cylindrical heat-shielding wall 25 in slightlyspaced-apart relation thereto. The heat-shielding wall 25 is secured tothe wall 21 by suitable means, as will readily be understood. Thecasing20 is placed on the flange 13 of the base 10 by way of the annularbottom wall 22. The cover 30 mounted on top of the casing 20 has formedtherein a central aperture 31 serving as a burnt gas discharge opening.

The cap-like member 40 is placed in the casing on top of the upstandingwall 23 thereof, as illustrated. The cap-like member 40 is also made ofsheet metal and generally frustoconical including a fiat horizontallyextending top wall 41 and a downwardly diverging conicallyshaped wall42, the inner surface of which engages the top edge of the upstandingwall 23 as at 43. The conical wall 42 is formed with a multitude ofapertures 44 serving as outlet passages through which burnt gases flowout. Each of the apertures 44 includes a slit having a horizontallyextending straight bottom edge 45 and an outwardly expanded or bulgedtop edge overlying said bottom edge in spaced-apart relation thereto.The apertures in this embodiment of the invention open downwardly.

The bottom wall 12 and annular flange 13 of the base 10 define a spacetogether with the upstanding wall 23 of the casing and the cap-likemember 40, the burner assembly 50 being arranged in the bottom portionof the space, as illustrated. The top portion of the space forms acombustion chamber where fuel ejected through the burner is burnt. Theburner assembly 50 includes a blower 51, an air delivery pipe 52connected to the outlet of said blower, and a mixing chamber 53communicating with the air delivery pipe 52 at the extremity thereof.Fuel gas is fed through a conduit 54 into the air delivery pipe 52intermediate its ends and mixed with air in the mixing chamber 53. Thefuel-air mixture is ejected upwardly from the mixing chamber 53 to burnin the combustion chamber above.

In this embodiment, the stack of heat-absorbing material 6t) fills thespace defined between the inner wall 25 of the casing and the cap-likemember 40 to surround the walls thereof reaching at the top a levelhigher than the top wall 41.

The water feeding device 70 includes a sprinkler head 72 disposed abovethe stack of heat-absorbing material and formed with a mulitude oforifices 71 having down- Wardly diverging axes. The water feeding device70 is secured at the sprinkler head 72 to the outer wall 21 of thecasing 20 by means of a support bar 73. A Water conduit 75 for feedingwater to the sprinkler head 72 extends downwardly along the innersurface of the inner wall 25 and further extends outwardly through theinner wall 25 and the outer wall 21 as indicated at 76 to a suitablewater supply source. Water to be heated is thus fed from the supplysource through the conduit 75 to the sprinkler head 72.

For the purpose of carrying the heated water collecting in the reservoir24 exteriorly of the heater, a conduit $1 is connected to the reservoir24 adjacent to its bottom and extends outwardly through the side wall 11of the base 14) to the point of use of the heated water. As

the water.

shown in FIG. 1, a window device 82 is provided 'for ob- I serving thestate of fuel combustionin the heater exteriorly of the casing thereof.i

In operation of the water heaterillustrated in FIGS. ;1' and 2, asapparent from thegforegoing description, fuel gas fed throughthe conduit54 into the air delivery pipe 52 of the burner assembly to be mixed withthe air delivered from the blower 51 flows upwardly through the pipe 52into the mixing chamber to be thoroughly mixed with the; air. Themixture flows out of the chamber toburn in the space above. The burntgases rise to flow outwardly through the mulitude of apertures 44 formedin the cap-like member 40 to be uniformly distributed into the stack ofheat-absorbing material 60 and thusvrises there= through while directlyheating the heat-absorbing material. Water fed through the conduit 75into the sprinkler cent roof members outwardly into the stack of heatabsorbing material 260. V i v The general function of the water heatershown in FIGS.

5 to 8 is similar to that, of the heater shown in FIGS. 1 and '2.Specifically, water is fed through the conduit 275 to the sprinkler head272 and ejected downwardly divergently 5 through the orifices 271 formedtherein. to flowfidown through the stack of heat-absorbing materialwhile being heated bythe burnt gases and the heat-absorbing materialhead 72 is ejected through the orifices 7 1 [formed therein downwardlydivergentlyto trickle down through the stack of heat-absorbing material60 While-making direct contact with the risinghot gases or with thesurfaces of the heatabsorbing material heated thereby. The water thusheated 7 while trickling down through'th-e heat-absorbing material iscollected in the annular reservoir and led out through the conduit 81to-the point of use as required.

With this arrangemenh itwill be appreciated that the I contact areabetween the trickling water and the rising:

gases or the heat-absorbing material isextremely large for the size of.the waterheater and thus'theheat content of the burnt gases issubstantially entirely. ransferred to an extremely highly efficientwater heater is provided produced from escaping exteriorly readily be.appreciated. v

Referring next to FIGS. 3 and4, a modified form of cap-like member 140is generally similar to the cap-like of the casing, as will rnem'ber iilexcept that it includesapertures 144 each tElk-r ing the form of a slithaving a horizontally extending straight top edgeand'an inwardly olfsetb ottom edge 149. Another embodiment of the present invention'shown inAccording'to the present invention, therefore,

which may be fed with fuel and water at highrates despite of its limitedsize. In the embodiment described above; the provision of the inner wall25. is effective to keep heat means defining 'a combustion chamber insaid casing and comingacaplike cover member defining an upper part ofsaid combustion .chamberin which combustion takes place, said cap-likemember having through, elongated apertures extending in acircumferential direction for allowing hot gases of combustion to flowout of said combustion chamber, means on'said cap-like covermemberdefining said apertures'opening ina downward direction, aplurality of stacked heat-absorbing bodies disposed around and oversaid'upper part of said come ,bustion chamber in immediatecontact-therewith to be heated by said gases fiowin'g out-10f saidcombustion chamberv apertures, means to sp'rink'le water on the-stack ofsaid heat-absorbing bodies for heat transfer from said hot gases andsaid bodies to thesprinkled water percolating therethrougli, means forcollecting the heated water comprising means defining a hot waterreservoir disposed at a level for receiving said water after percolatingthrough said heat-absorbing bodies and disposed beneath andcloseadjacent to said stacked heat-absorbing-bodies to hold the heated wateroutwardly of said @combustion chamber and in contactwith said combustionFIGS. 5 and--6 is generallysi'milar in construction to the I firstembodiment shown 'infFIGS.,1 and 2 except the following features. Partsof the second embodiment corre-. sponding to those of the firstembodiment are designated in FIGS. 5 and '6 by adding 200 to thereference numerals for the first embodiment.

Thecasing 220 of thesecond embodimentha's a simplified structurecompared with that of the first embodiment, lacking any inner wallcorresponding to the wall 2'5 arranged inside of the outer casingwall'fll of the first embodiment. The casing 220 also has an integraltop wall platform 291 provided [for the purpose. A burner assembly 250is' designed for use with liquid-duel.

230 in place of the cover 30. The stack of heat-absorbing material 2 60is supported at the bottom by an annular A furtherdistinctive feature ofthe embodiment shown in FIGS. 5 and '6 is a cap-likernember 240constructed as described below. 7

As illustrated in FIG. 7, the cap-likev member 240 includcs a top roofmember 246, anurnber ofintermediate roofmembers 247, a bottom roofmember 248, and three 7 rafters 249 interconnecting said roof members inspacedapart overlapping relation to each other to form a domelikestructure having annular spacings 244; Burnt gases flow through theseannular spacings 24 4 betweeri the adja- V chamber at least partiallycircumferentiallythereof, and a burner assembly in saidcombustioncharnber for burning a fuel in said combustion chamber,whereby said compact water heater is of reduced dimensions and can heatrelatively large amounts .of water with an improved efficiency. i A

2 A'compact water heater according to claim 1, in wh1chsa1dheat-absorbing bodies comprise a foraminou-s material.

References Cited by the Examiner UNITED STATESYPATENTS' V 4/08 Shipley V126-359 2,247,304 6/41 Mela 126-344 X 2,893,359v 7/59. .Magovern et a1.126-355 X FOREIGN PATENTS r 835,516 3/52 Germany. 582,792 11/46 GreatBritain. 575,458 7 '4/58 Italy. 4 1 162,078 7 8/33 Switzerland. 1

JAMES W. WESTHAVER, Primary Examiner. PERCY L. PATRmIc raminer. Y J

1. A COMPACT WATER HEATER COMPRISING, A CASING, MEANS DEFINING ACOMBUSTION CHAMBER IN SAID CASING AND COMING A CAP-LIKE COVER MEMBERDEFINING AN UPPER PART OF SAID COMBUSTION CHAMBER IN WHICH COMBUSTIONTAKES PLACE, SAID CAP-LIKE MEMBER HAVING THROUGH, ELONGATED APERTURESEXTENDING IN A CIRCUMFERENTIAL DIRECTION FOR ALLOWING HOT GASES OFCOMBUSTION TO FLOW OUT OF SAID COMBUSTION CHAMBER, MEANS ON SAIDCAP-LIKE COVER MEMBER DEFINING SAID APERTURES OPENING IN A DOWNWARDDIRECTION , A PLURALITY OF STACKED HEAT-ABSORBING BODIES DISPOSED AROUNDAND OVER SAID UPPER PART OF SAID COMBUSTION CHAMBER IN IMMEDIATE CONTACTTHEREWITH TO BE HEATED BY SAID GASES FLOWING OUT OF SAID COMBUSTIONCHAMBER APERTURES, MEANS TO SPRINKLE WATER ON THE STACK OF SAIDHEAT-ABSORBING BODIES FOR HERAT TRANSFER FROM SAID HOT GASES AND SAIDBODIES TO THE SPINKLED WATER PERCOLATING THERETHROUGH, MEANS FORCOLLECTING THE HEATED WATER COMPRISING MEANS DEFINING A HOT WATERRESERVOIR DISPOSED AT A LEVEL FOR RECEIVING SAID WATER AFTER PERCOLATINGTHROUGH SAID HEAT-ABSORBING BODIES AND DISPOSED BENEATH AND CLOSEADJACENT TO SAID STACKED HEAT-ABSORBING BODIES TO HOLD THE HEATED WATEROUTWARDLY OF SAID COMBUSTION CHAMBER AND IN CONTACT WITH SAID COMBUSTIONCHAMBER AT LEAST PARTIALLY CIRCUMFERENTIALLY THEREOF, AND A BURNERASSEMBLY IN SAID COMBUSTION CHAMBER FOR BURNING A FUEL IN SAIDCOMBUSTION CHAMBER, WHEREBY SAID COMPACT WATER HEATER IS OF REDUCEDDIMENSIONS AND CAN HEAT RELATIVELY LARGE AMOUNTS OF WATER WITH ANIMPROVED EFFICIENCY.